(1) Field of the Invention
This invention relates to a bottle with an ear made of synthetic resin prepared by injection orientation blow molding.
(2) Prior Art
In a bottle molded by injection molding a preform, and orientation blow molding portions other than a mouth portion of the preform into a thin wall-thickness configuration while holding the mouth portion, it is technically difficult to mold a part of the preform into an ear during orientation blow molding, unlike normal blow molding. Therefore, in case of mounting an ear, the ear is molded below the mouth portion integral with the preform.
Molding of such a bottle can be achieved by a cold parison system which molds a preform using a normal injection mold to mold the preform into a bottle by an orientation blow molding machine. However, this has been difficult to employ in the case of a hot parison system in which an operation from injection molding of a preform to orientation blow molding is carried out by a single apparatus.
In view of the foregoing, an attempt has been made to mount an ear after a bottle has been molded. In this case, however, a position at which an ear is mounted is limited to a portion above a support ring.
Therefore, the mouth portion of the bottle with an ear is formed longer than that of a normal bottle and a position at which an ear is mounted is high. Therefore, particularly in a large bottle, it is difficult to incline the bottle while holding the ear, often wanting in smooth pouring of contents.
Such a problem as just mentioned can be solved by an arrangement wherein a lower side of a mouth is formed to have a large diameter, and threads are provided in the outer periphery of the large diameter portion, to which the ear is threadedly mounted, as disclosed in British Registered Design No. 1,039,436. However, with injection orientation blow molding, it is impossible to orient blow mold portions approaching the large diameter portion without impairing the dimension of the thread formed in the outer peripheral side.
In injection orientation blow molding, the thread of the mouth portion, the support ring and the like remain injection molded with a view to maintaining molding accuracy. The wall portion made thin by the orientation blow molding is carried out from the underside of the support ring. For this reason, in the case where a large diameter portion having threads is formed below the support ring to threadedly mount an ear thereon, portions approaching the large diameter portion to remain thick-walled resulting from injection molding. As a result, the use of material per bottle increases, thus increasing cost.
Orientation blow molding has the merit in that since portions other than the mouth portion can be molded to have a thin wall-thickness, there can be obtained a bottle which is lighter than that obtained by the normal blow molding and is excellent in falling strength, because of which an increase of non-oriented portions left to be thin in wall-thickness is not unprefereable, and accordingly, a position of a large diameter portion at which an ear is mounted is limited to a portion near the mouth portion.
Moreover, mounting of an ear by means of a screw causes the ear to be easily loosened due to vibrations or the like, and a lower end of the ear is not connected to the body of a bottle and in a state in which the ear is easily disengaged. When the bottle is inclined to pour the contents, the load is concentrated on a bended portion at the upper portion of the ear to generate a flexture thereat. In case of an ear made of synthetic resin, a gripping portion thereof is separated.